This proposal is a Competitive Supplement to the ongoing Center for Metabolic Research on HIV and Drug Use (P30 DA 13 868, PI: Dr. Sherwood Gorbach). This program was funded in 2002 by NIDA as one of just two Centers for Drug Abuse and AIDS Research (CDAAR) in the country. The Center was formed to provide scientific resources for studying nutrition, endocrine and metabolic issues affecting drug users with and without HIV infection. The Center represents three East Coast Institutions: Tufts University in Boston, MA; Brown University in Providence, RI; and the Johns Hopkins Medical Institutions in Baltimore, MD. The coordinating center is at Tufts, which operates four of the six Cores of the Center: the Administrative, Developmental, Nutrition and Metabolism, and Epidemiology/Biostatistics Cores. The Endocrine Core is managed at Johns Hopkins and the Drug User Resources Core resides at Brown University. The purpose of this supplement is to expand the goals of the Center to 3 international settings: Argentina, India, and Vietnam. These countries were selected for their variation in geography, types and patterns of drug use, genetics, environment and HIV clade/subtype. The overall goals of this International supplement are: 1) To foster synergistic and collaborative research on nutritional and metabolic disorders in drug using populations around the world, 2) To provide the Core services of the Center to our international colleagues, 3) To initiate research studies in each of the 3 targeted countries, and 4) To establish an infrastructure for future studies. A secondary aim of this study will be to provide baseline nutrition, metabolic and virologic measures to 1) aid in the future selection of appropriate antiretroviral regimens, and 2) examine the potential metabolic complications of chronic infection/inflammation and antiretroviral therapies in future studies. This joint endeavor will be beneficial to both the international communities and the U.S. Results from our research studies will help to identify nutritional abnormalities in the local populations that may be amenable to interventions and expand our understanding of the causes and consequences of metabolic complications in chronic HIV infection in both the U.S. and abroad